CD45, also known as T200 or the Leukocyte Common Antigen (LCA), is encoded by the Protein Tyrosine Phosphatase Receptor type C (PTPRC) gene. The protein is expressed exclusively on cells of the haematopoietic system, and is one of the most abundant leukocyte cell surface glycoproteins (1). Different isoforms of CD45 are found on specific lymphocyte sub-populations, and are generated by alternative splicing. (2). At least four variants of the human protein can be distinguished by electrophoresis, with molecular weights ranging from 180-220kDa (3).
